// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package once_test

import (
	"once"
	"testing"
)

var ncall int

func call() { ncall++ }

func TestDo(t *testing.T) {
	ncall = 0
	once.Do(call)
	if ncall != 1 {
		t.Fatalf("once.Do(call) didn't call(): ncall=%d", ncall)
	}
	once.Do(call)
	if ncall != 1 {
		t.Fatalf("second once.Do(call) did call(): ncall=%d", ncall)
	}
	once.Do(call)
	if ncall != 1 {
		t.Fatalf("third once.Do(call) did call(): ncall=%d", ncall)
	}
}